Ultrasonic dental scaler: associated hazards

Efficacy of Oxygen-Enriched Mouthwash as a Pre-procedural Mouth Rinse Against Oral Microbes Produced During Ultrasonic Scaling

Aim Oxygen-enriched mouthwash products are based on oral topical oxygen therapy (OOT), which supports the formation of new blood vessels and the removal of toxins and waste products from the affected area and stimulates the synthesis of collagen. These antioxidant mouthwashes contain honey, lactoferrin, and sodium carbonate peroxide. Lactoferrin is an anti-inflammatory protein that binds the ferrous iron ions surrounding micro-organisms regulating bacterial growth. Hence, these products can be included as an adjunct to toothbrushing after oral surgeries and in the treatment of conditions like gingival inflammation and peri-implantitis. The aim of the study was to evaluate the efficacy of oxygen-enriched mouthwash as a pre-procedural mouth rinse against oral microbes in the aerosol produced during ultrasonic scaling. Materials and methods A total of 40 patients with an age range of 20-40 years who have been advised to undergo ultrasonic scaling were selected as study subjects and were randomly allocated to group 1 (test group; n = 20; blue®m mouthwash) and group 2 (control group; n = 20; chlorhexidine). After evaluating the initial bacterial load after the use of water (placebo) as pre-rinse on the patient's chest and shoulder areas in both experimental and control groups, both the group subjects were instructed to gargle with 10 ml of the provided mouth rinse for one minute before ultrasonic scaling procedure. Blood agar plates were placed at the patient's chest and shoulder area to collect the aerosol and were later incubated to assess the colony-forming units (CFUs). An independent t-test was done to compare the CFUs between the groups. Results The mean initial bacterial load after the use of water (placebo) as pre-rinse on the patients' chest area (122.4 ± 0.6) and shoulder area (109.3 ± 2.6) in the experimental group was similar to the bacterial load seen on the chest area (126.2 ± 4.8) and shoulder area (115.4 ± 3.8) in the control group. The CFUs found in blood agar plates placed on the chest (59.8 ± 2.5) and shoulder (35.3 ± 3.6) areas of patients in group 1 were less as compared to CFUs found in blood agar plates placed on the chest (104.8 ± 3.2) and shoulder (75.3 ± 2.8) areas of patients in group 2. The difference between both groups was statistically significant with a p-value of ≤0.05. Conclusion There is a reduction in the bacterial load in the aerosols that are emitted during the ultrasonic scaling procedure with the use of oxygen-enriched mouthwash as a pre-procedural rinse when compared with chlorhexidine.

Turbine effect on dental students' lateral pinch modulation and performances

BACKGROUND

Dental turbines can generate significant vibrations that may be transmitted to dentists' hands. The vibrations contribute to neural impairment and decrease dexterity over the long duration. It is unclear whether such vibration effects would be detected in the short time during the pre-clinical year of dentistry study.

AIMS

To investigate the effect of vibrations on lateral pinch modulation and manual performance of dentistry students.

METHODS

Four lateral pinch modulation tests by a square-shaped force sensing resistor (FSR) were administered to 30 dental students during their phantom course. Tests were performed with dominant and non-dominant hands at two time points: T0 (2 months after commencing phantom training) and T1 (end of phantom training). At each time point, students accomplished two manual performance tests on plastic teeth. Comparisons were made between lateral pinch modulation test scores at different times, considering the differences between hands and gender. The relationships between the FSR tests and manual performance were also determined.

RESULTS

The participating 19 female and 11 male students had a combined 50% response rate. At T1, the lateral pinch modulation for all tests significantly decreased for the dominant hand (P < 0.05) and non-dominant hand (P < 0.05). For the non-dominant hand at T1, the lateral pinch modulation of females significantly decreased as compared to males (P < 0.05). No significant correlations were found between lateral pinch modulation and manual tasks at T0 and T1.

CONCLUSIONS

The lateral pinch modulation of the fingers of dental students deteriorated after only 8 months of training at phantom (short-time exposure), with females at higher risk and possibly earlier symptoms manifestation.

Ultrasonic bone scalpel in spine surgery

Background

Spine surgery has always been considered technically demanding even in the hands of the most experienced surgeon on account of close proximity of vital soft tissue structures. Technical advancements over the last few decades have been crucial for the progress of this complex speciality which not only increased the surgical accuracy, but patient safety as well. Ultrasonic devices are one such innovation based on piezoelectric vibrations, patented by Fernando Bianchetti, Domenico Vercellotti, and Tomaso Vercellotti in 1988.

Methods

We did an extensive literature search on ultrasonic devices and their applications in the field of spine surgery.

Results

We present the various ultrasonic bone devices available including their physical, technologic and clinical aspects in spine surgery. We also attempt to cover the limitations and future advances of Ultrasonic bone scalpel (UBS) in particular, which would be interesting and informative for any spine surgeon who is novice in this field.

Conclusion

UBS has been found to be safe and effective in all forms of spine surgeries offering distinct advantages over conventional instruments, although limited by an inherent learning curve.

Complications and treatment errors in nonsurgical periodontal therapy

Nonsurgical periodontal therapy can be subject to iatrogenesis, which includes all the complications directly or indirectly related to a treatment. These complications include both operator-dependent harms and errors and the consequences and adverse effects of the therapeutic procedures. The complications arising following nonsurgical periodontal treatment can be categorized as intraoperative and postoperative and can affect both soft and hard tissues at an intra-oral and extraoral level. Soft-tissues damage or damage to teeth and restorations can occur while performing the procedure. In the majority of cases, the risk of bleeding associated with nonsurgical therapy is reported to be low and easily controlled by means of local hemostatic measures, even in medicated subjects. Cervicofacial subcutaneous emphysema is not a frequent extraoral intraoperative complication, occurring during the use of air polishing. Moreover, side effects such as pain, fever, and dentine hypersensitivity are frequently reported as a consequence of nonsurgical periodontal therapy and can have a major impact on a patient's perception of the treatment provided. The level of intraoperative pain could be influenced by the types of instruments employed, the characteristics of tips, and the individual level of tolerance of the patient. Unexpected damage to teeth or restorations can also occur as a consequence of procedural errors.

Educational Research Report Comparison of Three Canine Models for Teaching Veterinary Dental Cleaning

Veterinary dental cleaning prevents and treats periodontal disease, one of the most common diagnoses in small animal practice. Students learn to perform dental cleaning through deliberate practice, which can be gained through working on models. This study compared educational outcomes after students (n = 36) were randomized to practice on one of three dental cleaning models: a low-fidelity ceramic tile, a mid-fidelity three-dimensional (3D) printed canine skull model, or a high-fidelity canine head model. Students provided survey feedback about their model and later performed a dental cleaning on a canine cadaver head while being video-recorded. Experts (n = 10) provided feedback on each model. Experts agreed that all models were suitable for teaching dental cleaning, but the 3D skull and full head models were more suitable for assessing student skill (p = .002). Students were also more positive about the realism and features of those two models compared to the tile model. Students practicing on each of the models were equally effective at removing calculus from the cadavers' teeth. Students who learned on the tile model were a median of 4 minutes slower to remove calculus from their cadaver's teeth than students who trained on the canine head model. Although students may be more accepting of the 3D skull and full head models, all three models were equally effective at teaching the skill. Experts approved all models for teaching, but recommended the 3D skull or full head model if student skills were to be assessed. Low-fidelity models remain effective training tools with comparable learning outcomes.

Computer simulation of the SARS-CoV-2 contamination risk in a large dental clinic

COVID-19, caused by the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) virus, has been rapidly spreading worldwide since December 2019, causing a public health crisis. Recent studies showed SARS-CoV-2's ability to infect humans via airborne routes. These motivated the study of aerosol and airborne droplet transmission in a variety of settings. This study performs a large-scale numerical simulation of a real-world dentistry clinic that contains aerosol-generating procedures. The simulation tracks the dispersion of evaporating droplets emitted during ultrasonic dental scaling procedures. The simulation considers 25 patient treatment cubicles in an open plan dentistry clinic. The droplets are modeled as having a volatile (evaporating) and nonvolatile fraction composed of virions, saliva, and impurities from the irrigant water supply. The simulated clinic's boundary and flow conditions are validated against experimental measurements of the real clinic. The results evaluate the behavior of large droplets and aerosols. We investigate droplet residence time and travel distance for different droplet diameters, surface contamination due to droplet settling and deposition, airborne aerosol mass concentration, and the quantity of droplets that escape through ventilation. The simulation results raise concerns due to the aerosols' long residence times (averaging up to 7.31 min) and travel distances (averaging up to 24.45 m) that exceed social distancing guidelines. Finally, the results show that contamination extends beyond the immediate patient treatment areas, requiring additional surface disinfection in the clinic. The results presented in this research may be used to establish safer dental clinic operating procedures, especially if paired with future supplementary material concerning the aerosol viral load generated by ultrasonic scaling and the viral load thresholds required to infect humans.

Bio-Inspired Systems in Nonsurgical Periodontal Therapy to Reduce Contaminated Aerosol during COVID-19: A Comprehensive and Bibliometric Review

Background: On 30 January 2020, a public health emergency of international concern was declared as a result of the new COVID-19 disease, caused by the SARS-CoV-2 virus. This virus is transmitted by air and, therefore, clinical practices with the production of contaminant aerosols are highly at risk. The purpose of this review was to assess the effectiveness of bio-inspired systems, as adjuvants to nonsurgical periodontal therapy, in order to formulate bio-inspired protocols aimed at restoring optimal condition, reducing bacteremia and aerosols generation. Methods: A comprehensive and bibliometric review of articles published in English. Research of clinical trials (RCTs) were included with participants with chronic or aggressive periodontal disease, that have compared benefits for nonsurgical periodontal therapy (NSPT). Results: Seventy-four articles have been included. For probing depth (PPD) there was a statically significant improvement in laser, probiotic, chlorhexidine groups, such as gain in clinical attachment level (CAL). Bleeding on probing (BOP) reduction was statistically significant only for probiotic and chlorhexidine groups. There were changes in microbiological and immunological parameters. Conclusions: The use of bio-inspired systems in nonsurgical periodontal treatment may be useful in reducing risk of bacteremia and aerosol generation, improving clinical, microbiological and immunological parameters, of fundamental importance in a context of global pandemic, where the reduction of bacterial load in aerosols becomes a pivotal point of clinical practice, but other clinical trials are necessary to achieve statistical validity.

Comparative Evaluation of Efficacy of Chlorhexidine and Herbal Mouthwash as a Preprocedural Rinse in Reducing Dental Aerosols: A Microbiological Study

Objective. The risk to dentists, assistants, and patients of infectious diseases through aerosols has long been recognized. The aim of this study was to evaluate and compare the efficacy of commercially available preprocedural mouth rinses containing 0.2% chlorhexidine (CHX) gluconate, Befresh™ herbal mouthwash, and water in reducing the levels of viable bacteria in aerosols. Materials & Methods. This was a single-center, double-masked, placebo-controlled, randomized, three-group parallel design study. 30 patients (10 patients in each group) were recruited in the study. Patient rinsed mouth with 10 ml of CHX, 10 ml Befresh™, or 10 ml water. All the patients underwent supragingival ultrasonic scaling for a minimum of 30 min. The aerosol collection was done using a blood agar plate. The blood agar plates were kept approximately 12 inches from the patient’s mouth. The microbial culture was analyzed. The colony-forming unit (CFU) counting in all three groups was assessed using one-way ANOVA test to compare among the groups (p value <0.001). The intergroup comparison was done using the post hoc Tukey test. Result. There was a marked reduction in the CFU in the CHX group in all three areas. This was followed by Befresh™ (Sagar Pharmaceuticals) mouthwash. There was no reduction in the CFU of the water group. Conclusion. This study proves that a regular preprocedural mouth rinse could significantly reduce the majority bacteria present in aerosols generated by the use of an ultrasonic unit, and Befresh™ mouth rinse was found to be equally effective in reducing the aerosol contamination to 0.2% CHX gluconate.

Assessment of occupational hazards among dentists practicing in Mumbai

Aim:

To assess the awareness of various occupational hazards experienced and the preventive measures undertaken by the dentists in and around Mumbai.

Methods:

The present study was conducted using self-administered questionnaire, which was circulated to 200 dentists practicing in and around Mumbai. The questionnaire also included questions on personal information like age, gender, position (student or faculty), years of experience, and number of working hours per day. Those who completed the questionnaire form completely and willing to participate were only included in the study. The results were analyzed using SPSS version 22.0.

Results:

23.5% of the participants had the dental working experience more than 10 years and 28.5% dentists worked for ≥8 h. 69% were general practitioners and 40% of the participants treat nearly 10 to 20 patients per day. 45% of them experienced needle stick injury in clinical practice. 1.5% of dentists in our study admitted receiving some litigation from their patients.

Conclusion:

The present study indicated that occupational hazards, awareness about biological hazards, and preventive measures observed by dentists in Mumbai are generally consistent with published guidelines for infection control and also in accordance with the previous research. The majority of the dental practitioners were suffering from pain in the muscles of neck or back. Regular training and workshops can help lower such problems.

Qualitative and quantitative analysis of bacterial aerosols in dental clinical settings: Risk exposure towards dentist, auxiliary staff, and patients

INTRODUCTION

Cross-infection or contamination are the major threats related to any medical profession. Microorganisms present in the dental clinic can cause cross-infection to the dentist, auxiliary staff and even towards the patients.

AIMS

The study was conducted to assess the level of atmospheric microbial contamination and composition of aerosols before, during and after dental treatment procedures in four clinical settings.

METHODS AND MATERIALS

The present study was conducted over a two-week period in a private dental college setting. An equal number of culture medium plates (blood agar) were placed 30 min prior to the initiation of work sessions in the selected area and 1 h after the working session began and after 2 h of cessation of the working period. After the collection of samples, the culture medium plates were incubated aerobically at 37°C in an incubator for 48 h. The number of colonies was expressed as colonies per media plate. After counting the colonies bacterial cell morphology was determined by a microscopic examination using a Reichert-Jung Series 150 light microscope.

STATISTICAL ANALYSIS

Statistical analysis such as ANOVA test for mean values and post hock was done using statistical package for social sciences (SPSS).

RESULTS

It shows that colony count increased after the working session and which reduced by itself once the working session was concluded which was significant (P < 0.001). The highest increase in the mean colony count was found in the department of periodontology during the treatment sessions. In the blood agar plates, the S. epidermidis was found maximum 62%, micrococcus was 22%, diphtheroid was 10%, fungi 4% and the least S. aureus 2%.

CONCLUSION

This study demonstrates that aerosols increase during and after work sessions and, therefore, increases the chance for infectious agent transmission in clinical settings.

In-vivo compatibility between pacemakers and dental equipment

In-vitro studies suggest that electromagnetic interference can occur under specific conditions involving proximity between electronic dental equipment and pacemakers. At present, in-vivo investigations to verify the effect of using electronic dental equipment in clinical conditions on patients with pacemakers are scarce. This study aimed to evaluate, in vivo, the effect of three commonly used electronic dental instruments - ultrasonic dental scaler, electric pulp tester, and electronic apex locator - on patients with different pacemaker brands and configurations. Sixty-six consecutive non-pacemaker-dependent patients were enrolled during regular electrophysiology follow-up visits. Electronic dental tools were operated while the pacemaker was interrogated, and the intracardiac electrogram and electrocardiogram were recorded. No interferences were detected in the intracardiac electrogram of any patient during the tests with dental equipment. No abnormalities in pacemaker pacing and sensing function were observed, and no differences were found with respect to the variables, pacemaker brands, pacemaker configuration, or mode of application of the dental equipment. Electromagnetic interferences affecting the surface electrocardiogram, but not the intracardiac electrogram, were found in 25 (37.9%) patients, especially while using the ultrasonic dental scaler; the intrinsic function of the pacemakers was not affected. Under real clinical conditions, none of the electronic dental instruments tested interfered with pacemaker function.

The effect of dental scaling noise during intravenous sedation on acoustic respiration rate (RRa™)

BACKGROUND

Respiration monitoring is necessary during sedation for dental treatment. Recently, acoustic respiration rate (RRa™), an acoustics-based respiration monitoring method, has been used in addition to auscultation or capnography. The accuracy of this method may be compromised in an environment with excessive noise. This study evaluated whether noise from the ultrasonic scaler affects the performance of RRa in respiratory rate measurement.

METHODS

We analyzed data from 49 volunteers who underwent scaling under intravenous sedation. Clinical tests were divided into preparation, sedation, and scaling periods; respiratory rate was measured at 2-s intervals for 3 min in each period. Missing values ratios of the RRa during each period were measuerd; correlation analysis and Bland-Altman analysis were performed on respiratory rates measured by RRa and capnogram.

RESULTS

Respective missing values ratio from RRa were 5.62%, 8.03%, and 23.95% in the preparation, sedation, and scaling periods, indicating an increased missing values ratio in the scaling period (P < 0.001). Correlation coefficients of the respiratory rate, measured with two different methods, were 0.692, 0.677, and 0.562 in each respective period. Mean capnography-RRa biases in Bland-Altman analyses were -0.03, -0.27, and -0.61 in each respective period (P < 0.001); limits of agreement were -4.84-4.45, -4.89-4.15, and -6.18-4.95 (P < 0.001).

CONCLUSIONS

The probability of missing respiratory rate values was higher during scaling when RRa was used for measurement. Therefore, the use of RRa alone for respiration monitoring during ultrasonic scaling may not be safe.

Safety concerns of Piezoelectric Units in Implantable Cardioverter Defibrillator

PURPOSE

Evidence-based research appears to conflict on the potential risk of electromagnetic interference (EMI) between piezoelectric units (Pzs) and implantable cardioverters and defibrillators (ICDs). The purpose of this study was to observe whether the EMI produced by Pzs is hazardous for ICDs.

MATERIALS AND METHODS

A cross-sectional study of 6 Pzs was conducted in vitro for EMI using an ICD system. To simulate the human body's electrical resistance, electrographic recordings were made of the ICD and lead that were immersed in a bath of saline solution. The variables investigated were the presence of EMI, the distance between the ICD and the Pz, and signal intensity, damage, and type of damage to the ICD and lead. Each series of tests was repeated 3 times, beginning with a 15-second baseline recording (control), until all recording conditions had been covered. Each Pz was recorded under the following conditions: less than 2 cm from the tip of the ICD lead; less than 2 cm from the ICD; less than 2 cm from the lead body and coils; and 15 cm from the lead or the ICD (R4).

RESULTS

In the positive control (direct contact between the lead or the ICD with the Pz switched on), the ICD detected electrical activity as false heart activity. However, after covering all test conditions, no EMI was produced by the Pzs.

CONCLUSION

No EMI or permanent changes in the functioning of the ICD were detected in vitro.

Role of preprocedural rinse and high volume evacuator in reducing bacterial contamination in bioaerosols

Context:

Microbial contamination, which occurs during dental procedures, has been a potential threat to dental professionals and individuals. There has been a growing concern over the role of bioaerosols in spread of various airborne infections and also to reduce the risk of bioaerosol contamination.

Aims:

This study was to analyze the number of colony forming units (CFUs) in bioaerosols generated during ultrasonic scaling procedure as well as to evaluate the efficacy of chlorhexidine 0.12% (CHX) preprocedural mouth rinse and high volume evacuator (HVE) in minimizing the bioaerosol contamination.

Methods:

About 45 individuals were divided into three Groups A, B and C. These groups underwent ultrasonic scaling before and after the use of CHX (0.12%), HVE and combination of CHX (0.12%) and HVE. Bioaerosols were collected on blood agar plates which were incubated at 37°C for 48 h, and the CFUs were counted with manual colony counting device. A comparison was also done between A versus B, B versus C and A versus C groups.

Statistical Analysis Used:

Student's t-test.

Results:

We found a significant reduction in the CFUs when CHX (0.12%) preprocedural rinse (P < 0), or HVE (P < 0.001) or combination of both CHX (0.12%) and HVE were employed (P < 0.001). Maximum reduction in CFUs was observed when CHX (0.12%) and HVE were used in combination as compared to their individual use. A moderate significance was seen between A versus C groups but not with B versus C groups and A versus B groups.

Conclusion:

From our study, we conclude that individual methods such as CHX (0.12%) and HVE were useful to reduce the dental bioaerosols; however, combination of both CHX (0.12%) and HVE is more efficient to reduce dental bioaerosols than individual method.

Are some people suffering as a result of increasing mass exposure of the public to ultrasound in air?

New measurements indicate that the public are being exposed, without their knowledge, to airborne ultrasound. Existing guidelines are insufficient for such exposures; the vast majority refers to occupational exposure only (where workers are aware of the exposure, can be monitored and can wear protection). Existing guidelines are based on an insufficient evidence base, most of which was collected over 40 years ago by researchers who themselves considered it insufficient to finalize guidelines, but which produced preliminary guidelines. This warning of inadequacy was lost as nations and organizations issued 'new' guidelines based on these early guidelines, and through such repetition generated a false impression of consensus. The evidence base is so slim that few reports have progressed far along the sequence from anecdote to case study, to formal scientific controlled trials and epidemiological studies. Early studies reported hearing threshold shifts, nausea, headache, fatigue, migraine and tinnitus, but there is insufficient research on human subjects, and insufficient measurement of fields, to assess what health risk current occupational and public exposures might produce. Furthermore, the assumptions underpinning audiology and physical measurements at high frequencies must be questioned: simple extrapolation of approaches used at lower frequencies does not address current unknowns. Recommendations are provided.

Removal of simulated biofilm: a preclinical ergonomic comparison of instruments and operators

BACKGROUND

Periodontal scaling might cause musculoskeletal disorders, and scaling instruments might not only have different effectiveness and efficiency but also differ in their ergonomic properties. The present study assessed ergonomic working patterns of experienced (EO) and less experienced operators (LO) when using hand and powered devices for periodontal scaling and root planning.

METHODS

In an experimental study using periodontally affected manikins, sonic (AIR), ultrasonic (TIG) and hand instruments (GRA) were used by 11 operators (7 EO/4 LO) during simulated supportive periodontal therapy. Using an electronic motion monitoring system, we objectively assessed the working frequency and positioning of hand, neck and head. Operators' subjective evaluation of the instruments was recorded using a questionnaire.

RESULTS

Hand instruments were used with the lowest frequency (2.57 ± 1.08 s(-1)) but greatest wrist deviation (59.57 ± 53.94°). EO used instruments more specifically than LO, and generally worked more ergonomically, with less inclination of head and neck in both the frontal and sagittal planes, especially when using hand instruments. All groups found hand instruments more tiring and difficult to use than powered instruments.

CONCLUSION

Regardless of operators' experience, powered instruments were used more ergonomically and were subjectively preferred compared to hand instruments.

CLINICAL RELEVANCE

The use of hand instruments has potential ergonomic disadvantages. However, with increasing experience, operators are able to recognise and mitigate possible risks.

Influence of electronic apex locators and a gutta-percha heating device on implanted cardiac devices: an in vivo study

AIM

To evaluate the potential for electromagnetic interference (EMI) of electronic apex locators (EALs) and a gutta-percha heating device (HD) in patients with implantable cardiac pacemakers (ICPs) or cardioverter-defibrillators (ICDs).

METHODOLOGY

Two types of EALs (Romiapex A-15 and Novapex) and a HD (Touch'n Heat) were tested in patients followed in an outpatient clinic for cardiac arrhythmias. The heart rhythm was monitored on a computer screen during all experimental phases. After baseline data collection, the patient held each appliance (turned on) for 30 s, simulating their clinical use. If background noise was detected on the cardiac monitor, the sensitivity of the ICP/ICD was lowered by the cardiologist to evaluate the intensity of the detected EMI.

RESULTS

Twelve patients were evaluated (5 female and 7 male), and in nine instances, background noise in their cardiac devices related to the use of the endodontic devices was detected (6 patients). After lowering the sensitivity of the cardiac implants, three patients had more severe EMI in six instances, including pauses in ICP function. The presence of a symptomatic or asymptomatic pause was related to the patient's underlying heart rhythm. The HD device produced background noise more often compared to EALs. These were associated with more severe types of EMI.

CONCLUSION

The EALs and gutta-percha HD were capable of causing background noise detection or pauses in cardiac implants in vivo. The use of electronic dental devices nearby patients with cardiac implants should be carefully considered in clinical practice.

Efficacy versus health risks: An in vitro evaluation of power-driven scalers

Background:

Power-driven instrumentation of root surfaces during supportive periodontal therapy is an alternative to hand instrumentation. The purpose of this pilot in vitro study was to investigate the efficacy of sub- and supragingival plaque removal with a sonic (AIR: Synea, W and H, Bürmoos, Austria) and two ultrasonic devices (TIG: Tigon+, W and H, Bürmoos, Austria; VEC: Vector, Dürr, Bietigheim-Bissingen, Germany) as well as the health-risk for dental professionals during treatment.

Materials and Methods:

The power-driven devices were utilized to remove plaque from model teeth in dummy heads. The percentage of residual artificial plaque after 2 min of supra- or subgingival instrumentation was calculated by means of image-processing techniques at four sites (n = 576) of each tooth. The Health-Risk-Index (HRI: spatter/residual plaque quotient) with the different power-driven devices was assessed during treatment.

Results:

The smallest amounts of residual plaque were found for the sonic device AIR (8.89% ± 10.92%) and the ultrasonic scaler TIG (8.72% ± 12.02%) (P = 0.707). Significantly more plaque was remained after the use of the ultrasonic scaler VEC (18.76% ± 18.07%) (P < 0.001). Irrespectively of the scaler, efficacy was similar sub- (10.7% ± 11.6%) and supragingivally (13.5% ± 17.2%) (P = 0.901). AIR/TIG demonstrated equal residual amounts of plaque sub- (P = 0.831) as well as supragingivally (P = 0.510). However, AIR/VEC and TIG/VEC were significantly in favor of AIR and TIG (P < 0.001). In contrast, the lowest HRI was found after using VEC (0.0043) and differed considerably for AIR (0.2812) and TIG (0.0287).

Conclusion:

Sonic devices are as effective as ultrasonic devices in the removal of biofilm but bear a higher risk to the dental professional's health concerning the formation of spatter.

Interference between dental electrical devices and pacemakers or defibrillators: results from a prospective clinical study

BACKGROUND

The authors aimed to determine whether electrical dental devices would interfere with the function of cardiac pacemakers or implantable cardioverter defibrillators (ICDs) in humans.

METHODS

The authors exposed asymptomatic nonpacemaker-dependent patients to commonly used electrical dental equipment (for example, battery-operated curing lights, ultrasonic baths, ultrasonic scalers, electric pulp testers, and electric toothbrushes) in an outpatient cardiology clinic. The authors operated dental devices at various distances and programmed cardiac devices to sense and pace. The authors obtained cardiac tracings using a cardiac programming unit and a cardiac provider who noted any interference interpreted the results in real time.

RESULTS

The authors enrolled 32 consecutive patients and tested 12 pacemakers and 20 ICDs. They did not observe any significant clinical interference in sensing and pacing functions in any patient; however, they noted minor interference without clinical impact in the telemetry from the cardiac programming unit during use of the ultrasonic scaler and bath.

CONCLUSIONS

The findings of this prospective study suggest that electrical devices commonly used in dental practices do not interfere with the sensing and pacing of contemporary cardiac patients' pacemakers or ICDs. However, they do interfere with the telemetry from the cardiac programming unit, without any clinical impact on patient safety. These findings should help in the development of clinical guidelines regarding dental management of patients with pacemakers or ICDs.

PRACTICAL IMPLICATIONS

Electrical dental devices (for example, ultrasonic baths, ultrasonic scalers) induced minor interference with programmers that interrogate cardiac devices implanted in patients; however, overall, dental devices do not appear to interfere with pacemakers' and defibrillators' pacing and sensing function.

Acoustic Noise Levels of Dental Equipments and Its Association with Fear and Annoyance Levels among Patients Attending Different Dental Clinic Setups in Jaipur, India

BACKGROUND

Noise is a source of pervasive occupational hazard for practicing dentists and the patients. The sources of dental sounds by various dental equipments can pose as a potential hazard to hearing system and add to the annoyance levels of the patients. The aim of the study was to analyze the noise levels from various equipments and evaluate the effect of acoustic noise stimulus on dental fear and annoyance levels among patients attending different dental clinic setups in Jaipur, India.

METHODOLOGY

The sampling frame comprised of 180 patients, which included 90 patients attending 10 different private clinics and 90 patients attending a Dental College in Jaipur. The levels of Acoustic Noise Stimulus originating from different equipments were determined using a precision sound level meter/decibulometer. Dental fear among patients was measured using Dental Fear Scale (DFS).

RESULTS

Statistical analysis was performed using chi square test and unpaired t-test. The mean background noise levels were found to be maximum in the pre-clinical setup/ laboratory areas (69.23+2.20). Females and the patients attending dental college setup encountered more fear on seeing the drill as compared to the patients attending private clinics (p<0.001).

CONCLUSION

The sources of dental sounds can pose as a potential hazard to hearing system. It was analyzed that the environment in the clinics can directly have an effect on the fear and annoyance levels of patients. Hence it is necessary control the noise from various dental equipments to reduce the fear of patients from visiting a dental clinic.

Effects of external electrical and magnetic fields on pacemakers and defibrillators: from engineering principles to clinical practice

The overall risk of clinically significant adverse events related to EMI in recipients of CIEDs is very low. Therefore, no special precautions are needed when household appliances are used. Environmental and industrial sources of EMI are relatively safe when the exposure time is limited and distance from the CIEDs is maximized. The risk of EMI-induced events is highest within the hospital environment. Physician awareness of the possible interactions and methods to minimize them is warranted.

Microbial biofilm modulation by ultrasound: current concepts and controversies

Biofilm elimination is often necessary during antimicrobial therapy or industrial medical manufacturing decontamination. In this context, ultrasound treatment has been frequently described in the literature for its antibiofilm effectiveness, but at the same time, various authors have described ultrasound as a formidable enhancer of bacterial viability. This discrepancy has found no solution in the current literature for around 9 years; some works have shown that every time bacteria are exposed to an ultrasonic field, both destruction and stimulation phenomena co-exist. This co-existence proves to have different final effects based on various factors such as: ultrasound frequency and intensity, the bacterial species involved, the material used for ultrasound diffusion, the presence of cavitation effects and the forms of bacterial planktonic or biofilm. The aim of this work is to analyze current concepts regarding ultrasound effect on prokaryotic cells, and in particular ultrasound activity on bacterial biofilm.

Mechanized scaling with ultrasonics: Perils and proactive measures

Mechanized scaling for plaque removal is a routine procedure in the practice of periodontics. Though it appears innocuous by itself, there are retinues of hazards associated with it on various organ systems in the body. Some of these unwanted effects and measures to avoid or ameliorate the same are elaborated here. Exposure to ultrasonic scaling is inevitable before any other treatment procedure. Aerosol contamination, vibrational hazards, thermal effects on the dental pulp, altered vascular dynamics, disruption in electromagnetic device, diminished hearing and dental unit waterline contamination are some of the probable off-shoots a patient has to bear. Uses of barrier devices, proper attention to usage of equipment, protection for ear and water treatment are few of solutions for the same. Though documented evidence for the existence of all effects is lacking, it is never the less significant for the overall safety of the patient. A conscientious clinician should therefore inculcate the available steps to overcome the hazards of ultrasonic scaling.

Effects of piezoelectric units on pacemaker function: an in vitro study

INTRODUCTION

The use of piezoelectric units on patients with pacemakers is generally discouraged, although there is no empirical evidence of the effects of current piezoelectric units on pacemaker activity in vitro.

METHODS

Four piezoelectric units (Piezosurgery3, Piezotome, Piezotome2, and Variosurg) and 2 magnetostriction units (Piezotome and Piezotome2) were tested for electromagnetic interference (EMI) with the SENSIA SESR01 pacemaker from Medtronic. The pacemaker, with a single electrode, was immersed in a saline-solution bath and adjusted between 400 and 800 ohms to simulate the electrical resistance of the human body and to register and to produce electrographic recordings. The pacemaker was tested with each ultrasonic device to analyze the presence of EMI at different distances, with the ultrasound switched on, switched off, and during operation. If any of the devices produced interference, the characteristics of the interference were categorized.

RESULTS

In the positive control (direct contact between either the electrode or the generator and the ultrasound device when this was switched on), the pacemaker detected electrical activity as false heart activity. When all the scenarios and distances had been covered, no EMI was produced by the ultrasound units.

CONCLUSIONS

No EMI was detected during the testing of the piezoelectric or magnetostriction units in this in vitro model of pacemaker use.

Do ultrasonic dental scalers interfere with implantable cardioverter defibrillators? An in vivo investigation

OBJECTIVES

To test the in vivo effects of an ultrasonic dental scaler on various implanted cardioverter defibrillator (ICD) models.

METHODS

12 consecutive patients with ICDs had continuous both electrocardiogram monitoring and device interrogation to detect interferences during the use of an ultrasonic dental scaler.

RESULTS

No interferences were detected by any ICD. Evaluation of the electrocardiograms for each patient failed to show any abnormalities in pacing during testing.

CONCLUSION

The results of this study suggest that the routinary clinic use of piezoelectric dental scalers do not interfere with the functioning of any of the tested ICDs.

CLINICAL SIGNIFICANCE

Ultrasonic dental scalers have been suspected of electromagnetic interference (EMI) with the normal functioning of ICDs and the use of this type of equipment for patients with these devices has been controversial. This is the first in vivo study to investigate EMI of ICD activity during the operation with ultrasonic dental scaler.

Effect of periodontal treatment on the clinical parameters of patients with rheumatoid arthritis: study protocol of the randomized, controlled ESPERA trial

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disorder that leads to joint damage, deformity, and pain. It affects approximately 1% of adults in developed countries. Periodontitis is a chronic oral infection, caused by inflammatory reactions to gram-negative anaerobic bacteria, and affecting about 35 to 50% of adults. If left untreated, periodontitis can lead to tooth loss. A significant association has been shown to exist between periodontitis and RA in observational studies. Some intervention studies have suggested that periodontal treatment can reduce serum inflammatory biomarkers such as C-reactive protein, or erythrocyte sedimentation rate. We hypothesize that periodontitis could be an aggravating factor in patients with RA, and that its treatment would improve RA outcomes. The aim of this clinical trial is to assess the effect of periodontal treatment on the biological and clinical parameters of patients with RA.

METHODS/DESIGN

The ESPERA (Experimental Study of Periodontitis and Rheumatoid Arthritis) study is an open-label, randomized, controlled trial. Subjects with both RA and periodontitis will be recruited at two university hospitals in southwestern France. In total, 40 subjects will be randomized into two arms (intervention and control groups), and will be followed up for 3 months. Intervention will consist of full-mouth supra-gingival and sub-gingival non-surgical scaling and root planing, followed by systemic antibiotic therapy, local antiseptics, and oral hygiene instructions. After the 3-month follow-up period, the same intervention will be applied to the subjects randomized to the control group.The primary outcome will be change of in Disease Activity Score in 28 Joints (DAS28) at the end of the follow-up period. Secondary outcomes will be the percentages of subjects with 20%, 50%, and 70% improvement in disease according to the American College of Rheumatology criteria. Health-related quality of life assessments (the Health Assessment Questionnaire and the Geriatric Oral Health Assessment Index) will also be compared between the two groups.

DISCUSSION

Evidence-based management of potential aggravating factors in subjects with active RA could be of clinical importance, yet there are few randomized controlled trials on the effect of periodontal treatment on the clinical parameters of RA. The ESPERA trial is designed to determine if non-surgical periodontal treatment could improve clinical outcomes in patients with active RA, and the quality of life of these patients.

TRIAL REGISTRATION

The ESPERA Trial was registered in Current Controlled Trials [ISRCTN79186420] on 2012/03/20. The trial started recruiting on 2012/03/06.

Sonosurgery for atraumatic tooth extraction: a clinical report

The preservation of an intact labial plate during tooth extraction is a critical determinant of whether an immediate implant can be placed and is also an important predictor of the esthetic result. The purpose of this clinical report was to present a method for atraumatic tooth extraction by using an air-driven sonic instrument with specially designed inserts. This surgical technique provides the clinician with an efficient method for atraumatic tooth extraction and preservation of an intact labial plate.

Occupational Hazards in Modern Dentistry

Dentists, as well as other dental personnel are constantly exposed to a number of specific occupational hazards. These cause the appearance of various ailments, specific to the profession, which develop and intensify with years. Despite numerous technical advances in recent years, many occupational health problems still persist in modern dentistry. These include percutaneous exposure incidents (PEI), exposure to infectious diseases, radiation, dental materials, musculoskeletal disorders (MSD), dermatitis, respiratory disorders, eye injuries and psychological problems. PEI remains a particular concern, as there is an almost constant risk of exposure to serious infectious agents. Aside from biological hazards, dentists continue to suffer a high prevalence of MSD, especially of the back, neck and shoulders. Awareness regarding these occupational hazards and implementation of preventive strategies can provide a safe working environment for all the dental personnel. There is also a need for continuing dental education programs in dentistry so that dentists can update themselves with the latest and newer techniques and materials.

How to cite this article

Mohammed NS, Shaik MA. Occupational Hazards in Modern Dentistry. Int J Experiment Dent Sci 2013;2(1):33-40.

Thermal irritation of teeth during dental treatment procedures

While it is reasonably well known that certain dental procedures increase the temperature of the tooth's surface, of greater interest is their potential damaging effect on the pulp and tooth-supporting tissues. Previous studies have investigated the responses of the pulp, periodontal ligament, and alveolar bone to thermal irritation and the temperature at which thermal damage is initiated. There are also many in vitro studies that have measured the temperature increase of the pulp and tooth-supporting tissues during restorative and endodontic procedures. This review article provides an overview of studies measuring temperature increases in tooth structures during several restorative and endodontic procedures, and proposes clinical guidelines for reducing potential thermal hazards to the pulp and supporting tissues.

Root damage induced by intraosseous anesthesia. An in vitro investigation

OBJECTIVES

The principle of the intraosseous anesthesia (IOA) relies on the perforation of the cortical plate of the bone for direct application of the local anesthetic solution into the underlying cancellous structures. During this procedure, IOA needles might accidentally come in contact with the tooth roots. The aim of the current in vitro study was to examine the consequences of this 'worst case scenario' comparing five commercially available IOA systems.

MATERIAL AND METHOD

Extracted human roots were randomly perforated using five different IOA systems with a drilling time ≤5s. To simulate normal in vivo conditions, the roots were kept humid during the drilling procedure. Data was statistically evaluated using F-test (SPSS16, SPSS Inc., Chicago, USA) and the significance level was set at p ≤ 0.05.

RESULTS

All examined systems resulted in root perforation. Drill fractures occurred in either none 0% (Quicksleeper, Anesto, Intraflow, Stabident) or 100% (X-Tip) of the applications. Excessive heat generation, as evident by combustion odor as well as metal and tooth discoloration, appeared in 30% (Quicksleeper), 40% (Anesto), 60% (Intraflow), 90% (Stabident) and 100% (X-Tip) of all perforations.

CONCLUSION

Within the limits of in-vitro studies, the results show a potential for irreversible root damage that might be inflicted by an improper use of IOA systems.

Efficacy of 0.2% tempered chlorhexidine as a pre-procedural mouth rinse: A clinical study

OBJECTIVE

Our objective was to determine the efficacy of pre-procedural rinsing with chlorhexidine in reducing bacterial aerosol contamination during use of ultrasonic scaler and comparing the efficacy of water, non-tempered chlorhexidine and tempered chlorhexidine in reducing bacterial count in aerosols when used as a pre-procedural rinse.

MATERIALS AND METHODS

The study was designed to include 30 systemically healthy patients in different age groups. The patients were divided randomly into 3 groups (I, II, III) of 10 patients each to be administered with sterile water, non tempered chlorhexidine and tempered chlorhexidine, respectively, as a pre-procedural rinse. The aerosol produced by the ultrasonic unit was collected at 3° clock, 6° clock and 12° clock positions on blood agar plates within a range of 4 feet in all the three groups. The blood agar plates were incubated for 48 hours and the total number of colony forming units (CFUs) were counted and statistically analyzed.

RESULTS

The results showed that CFU in group III and group II were significantly reduced when compared to group I with F=1084.92, P<0.001 (ANOVA). Also, CFU in group III was significantly reduced when compared to group II with P<0.001.

CONCLUSIONS

Pre-procedural rinse can significantly reduce the viable microbial content of dental aerosols and tempered chlorhexidine was more effective than non-tempered chlorhexidine.

Noise levels in a dental teaching institute - A matter of concern!

OBJECTIVE

To measure and assess the noise levels produced by various dental equipments in different areas of a dental institution and to recommend improvements if noise levels are not within permissible limits.

MATERIAL AND METHODS

Sound levels were measured at three different areas of a dental institution where learning and teaching activities are organized. The sound level was measured using a sound level meter known as 'decibulolmeter'. In each area the noise level was assessed at two positions-one, at 6 inches from the operators ear and second, at the chairside instrument trolley. Noise levels were also assessed from a central location of the clinic area when multiple equipments were in operation simultaneously.

RESULTS

Dental laboratory machine, dental hand-piece, ultrasonic scalers, amalgamators, high speed evacuation, and other items produce noise at different sound levels which is appreciable. The noise levels generated varied between 72.6 dB in pre-clinics and 87.2 dB in prosthesis laboratory. The results are comparable to the results of other studies which are conducted elsewhere. Although the risk to the dentists is lesser, but damage to the hearing is possible over prolonged periods.

CONCLUSION

Higher noise levels are potentially hazardous to the persons working in such environments especially in the laboratory areas where noise levels are exceeding the permissible limits. Key words:Noise level, equipment, hearing loss, risk, working areas.

Removal of failed crown and bridge

Crown and bridge have life span of many years but they fail for a number of reasons. Over the years, many devices have been designed to remove crowns and bridges from abutment teeth. While the removal of temporary crowns and bridges is usually very straightforward, the removal of a definitive cast crown with unknown cement is more challenging. Removal is often by destructive means. There are a number of circumstances, however, in which conservative disassembly would aid the practitioner in completing restorative/endodontic procedures. There are different mechanisms available to remove a failed crown or bridge. But there is no information published about the classification of available systems for crown and bridge removal. So it is logical to classify these systems into different groups which can help a clinician in choosing a particular type of system depending upon the clinical situation. The aim of this article is to provide a classification for various crown and bridge removal systems; describe how a number of systems work; and when and why they might be used. A PubMed search of English literature was conducted up to January 2010 using the terms: Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure. Additionally, the bibliographies of 3 previous reviews, their cross references as well as articles published in various journals like International Endodontic Journal, Journal of Endodontics and were manually searched.

Key words:Crown and bridge removal, Crown and bridge disassembly, Crown and bridge failure.

Bio-effects and safety of low-intensity, low-frequency ultrasonic exposure

Low-frequency (LF) ultrasound (20-100 kHz) has a diverse set of industrial and medical applications. In fact, high power industrial applications of ultrasound mainly occupy this frequency range. This range is also used for various therapeutic medical applications including sonophoresis (ultrasonic transdermal drug delivery), dentistry, eye surgery, body contouring, the breaking of kidney stones and eliminating blood clots. While emerging LF applications such as ultrasonic drug delivery continue to be developed and undergo translation for human use, significant gaps exist in the coverage of safety standards for this frequency range. Accordingly, the need to understand the biological effects of LF ultrasound is becoming more important. This paper presents a broad overview of bio-effects and safety of LF ultrasound as an aid to minimize and control the risk of these effects. Its particular focus is at low intensities where bio-effects are initially observed. To generate a clear perspective of hazards in LF exposure, the mechanisms of bio-effects and the main differences in action at low and high frequencies are investigated and a survey of harmful effects of LF ultrasound at low intensities is presented. Mechanical and thermal indices are widely used in high frequency diagnostic applications as a means of indicating safety of ultrasonic exposure. The direct application of these indices at low frequencies needs careful investigation. In this work, using numerical simulations based on the mathematical and physical rationale behind the indices at high frequencies, it is observed that while thermal index (TI) can be used directly in the LF range, mechanical index (MI) seems to become less reliable at lower frequencies. Accordingly, an improved formulation for the MI is proposed for frequencies below 500 kHz.

Evaluation of a dental model for training veterinary students

Periodontal disease has deleterious effects on an animal's health and potentially serious implications for its welfare. Consequently, veterinarians frequently perform routine periodontal treatment in small-animal practice. One would therefore assume that small-animal dentistry would constitute a core component of a veterinary curriculum. However, most practitioners received little or no formal training in dentistry during their veterinary degrees, and the amount of instruction students currently receive is variable, often with limited opportunities to practice. At the Royal Veterinary College, a prototype dental model was developed to address the lack of practical training; it was made using ceramic tiles, silicone sealant, and grout to emulate teeth, gingiva, and calculus, respectively. A study was conducted with third-year veterinary students to compare the outcomes of learning to perform a professional dental cleaning using a model (group A) or a video (group B). Performance was assessed using an objective structured clinical examination. Students in group A scored significantly better than those in group B (p<.001). All students also completed a questionnaire evaluating attitudes toward the use of a dental model in learning dentistry-related skills. All students identified a model as a potentially valuable learning tool to supplement existing teaching methods and facilitate the acquisition of small-animal dentistry skills. The dental model has the potential to equip students with useful, practical skills in a safe and risk-free environment.

Piezoosteotomy in orthognathic surgery versus conventional saw and chisel osteotomy

INTRODUCTION

Piezoosteotomy was assessed as alternative osteotomy method in orthognathic surgery regarding handling, time requirement, nerve and vessel impairment.

MATERIALS AND METHODS

In this comparative clinical experience, 90 patient's orthognathic surgery procedures were performed in typical distribution prospectively by piezoosteotomy: 34 (38%) monosegment, 47 (52%) segmented LeFortI osteotomies, 94 (52%) sagittal split osteotomies, 11 (12%) symphyseal, and 4 (2%) mandibular body osteotomies. As controls served 90 retrospective patients with conventional saw and chisel osteotomy: 58 (64%) monosegment, 27 (30%) segmented LeFortI osteotomies, 130 (72%) sagittal split, and 4 (4%) symphyseal osteotomies.

RESULTS AND DISCUSSION

Piezoosteotomies were individually designed to interdigitate the jaw segments after repositioning. The pterygomaxillary suture weakened angulated tools; auxiliary chisels were required in 100% of cases for the nasal septum and lateral nasal walls, in 33% for pterygoid processes. The dorsal maxilla as the pterygoid process were easily reduced; 15% mandibular osteotomies required sawing, while the lingual dorsal osteotomy was performed by manual feedback due to limited visibility. Bloodloss decreased from average 537 +/- 208 ml vs. 772 +/- 338 ml (p = 0.0001). Operation time remained unchanged: 223 +/- 70 min vs. 238 +/- 60 min (p = 0.2) for a conventional bimaxillary procedure. Clinical courses and reossification were unobtrusive. Alveolar inferior nerve sensitivity was retained in 98% of the piezoosteotomy collective versus 84% of controls (p = 0.0001) at 3 months postoperative testing.

CONCLUSION

Piezoelectric osteotomy did not prolong the operation and reduced blood loss as alveolar nerve impairment. A few patients required additional sawing or chisel. Piezoelectric screw insertion as complex osteotomies may be initiated to simplify the procedure and increase segment interdigitation after repositioning as to minimize the osteofixation time and dimensions.